Maps: Two-dimensional, scaled representations of Earth surface - show spatial data (data with locational component)Cartography (map-making) involves 5 design decisions – based on purpose of map

Projection Simplification Scale Aggregation Type of Map (thematic* or

reference)

THEMATIC MAPS – depict characteristics of places

Categorical type

- Depict areas that are different in kind

- Use several distinct colors to show different categories

desert forest tundra

Examples: climates, religionsChoropleth type

- Depict areas that are different in amount

- Use shades of similar colors to show different values

high value medium low value

Examples: population density, literacy rates

Example of “categorical map”

Example of “choropleth map”

Human Development Index (HDI) Rankings

Includes GNI/PPP, Literacy, and Life Expectancy

Which regions have high HDI?

Which regions have low HDI?

Which places are exceptions?

Isoline type(Average Daily Solar Radiation)Lines connect points of equal value Dot Density type

(Wisconsin Acreage in Potatoes)

Each dot represents a frequency of mapped

variable

Proportional Symbol Map (Graduated Circle type)

Size of symbol varies in relation to frequency or intensity of the mapped

variable

Proportional Symbol Map (Flow Vector type)

Sample Map Projections

Mercator

Systematic methods of transferring a spherical surface to a flat map

Distortion must occur in either size, shape,

distance, or direction – all projections are

compromises

Robinson Polar

Equal-Area projections best where purpose is to compare distributions of a variable

between places

(They distort shapes to make sizes correct.)

What impressions do you get from this map?

smaller scale

Sample Area Covered Fraction Scale Verbal ScaleWorld 1:78,000,000 1 in = 1,250 mi No. America 1:36,000,000 1 in = 570 miCentral U.S. 1: 4,000,000 1 in = 64 miAAA Colo map 1: 1,267,200 1 in = 20 mi

larger scale

Smaller-scale shows more land area in less detail. Used to show global patterns.

Larger-scale shows less land area in more detail. Used on local maps.

Map Scale The ratio of map distance to earth distance, measured in the same units

The scale at which one analyzes an issue is critical DIA – Only major U.S. airport built since 1980

At the national scale, why did the location of this airport make sense?

At the local scale, why was it necessary to locate the airport where it is?

Percent of 1990 pop age 25+ with bachelor's degree

Data aggregated by State

Map Aggregation The level of detail for dividing a thematic map into

geographic units

Ranges from coarse divisions

(e.g., by countries) to fine divisions (e.g., by zip

codes)

Percent of pop age 25+

with bachelor's degree (1990)

Note what information is lost at higher levels of

aggregation

Aggregated by State

(northeast close-up)

Aggregated by County (WV, MA)

Source: M. Gastner, C. Shalizi, and M. Newman, University of Michiganhttp://www-personal.umich.edu/~mejn/election/

State results, by land area

County results, by land area

State results, by population

County results, by population

2004 Presidential Election Red = Bush; Blue = Kerry

Source: M. Gastner, C. Shalizi, and M. Newman, University of Michiganhttp://www-personal.umich.edu/~mejn/election/

2004 Presidential Election

Red = Solidly Bush (70% +)

Purples = divided … redder = Bush majority; bluer = Kerry majority

Blue = Solidly Kerry (70%+)

By land area By population

Spatial Thinking(Phil Gersmehl, Research in Geographic Education, 2006)

Pattern Analysis: Density vs. Dispersion

Which square mile has the higher density, (a) or (b)?

Various Pattern Arrangements

What phenomena could explain the patterns shown in

A, B, and C?

Connections

What kinds of things

are symbolized by lines on this map?

Combination of climate, agriculture, and industry explains population density

patterns

Where are some patterns that illustrate this?

Denver metro area

How does this map illustrate the aura

or zone of influence for

Denver?

How are hierarchies

symbolized on this map?

For which kinds of services does Denver’s aura extend beyond

this map?

Where could you define a region of “Elvis-lovers”?

Where are the exceptions?

Where are the outliers?

Compare the Pacific coasts of North and

South America

Which places have

analogous climates?

Spot any spatial correlations?

Middle & South America Agricultural Regions (left) and Population Density

(below)

Christian

An example of the importance of spatial thinking

TURKIC (Altaic Language Family)

IRANIAN (Indo-European Language Family)

SEMITIC (Afro-Asiatic Language Family)

Diversity,exceptions,and edgescan make

forinteresting

case studiesor

examples

Iraq’s population is 29 million: sixty percent are Shi’a Arab, mostly in the south.

Sunni Arabs are concentrated in the center (western Iraq is sparsely populated).

Over 4 million Iraqis in northern Iraq are Kurdish. Baghdad is a transition zone.

Saudi Arabia Kuwait

Iran

Jordan

Syria

Turkey

Iraq Ethnic Groups

Knowledge of cultural regions, boundaries, and transitions is necessary

for understanding conflicts